This invention relates to remote insertion of connector pins within an electrical cabinet, particularly employing flexible drive rods.
Many applications, including heavily packed computer cabinets and other equipment employing electrically interconnected circuit boards are often configured for electrical connections to an interface board, such as a mother board, back plane, or another circuit board buried deep within the cabinet. Connections in such inaccessible locations generally require blind insertion of connectors on a back edge of the circuit board into mating connectors on the inaccessible interface board. Furthermore, access is generally provided only through a single opening in the cabinet opposite the connector interface. Thus, the board installer is faced with blindly aligning connectors on the circuit board with mating connectors on the back wall of the cabinet. Several methods are known for providing initial alignment of the board within the cabinet. For example, the cabinet wall is often provided with slots configured to accept an edge of the circuit board and align it within the cabinet. In another example, bayonet pins are provided on the back edge of the circuit board to mate with precision holes positioned in the back wall of the cabinet.
In instances where known circuit board alignment mechanisms often provide proper mating of connectors, the alignment they provide may be too gross to safely mate connectors having large numbers of very delicate connections. Although the housings of such connectors are typically formed with corresponding guide pins or another lead in mechanism, an aggressive installation often does not provide sufficient opportunity for slender male pins to properly align with correspondingly narrow female receptacles. In such instances, the fragile pins generally require a gentle easing together of the mating connector elements for successful insertion of the slender male pins to avoid bending and other damage. One or more of the male pins may fail to completely align with its female counterpart and become bent or completely crushed during installation. The connector installation device of the present invention provides both the initial alignment within the cabinet and the controlled force needed to gently and certainly engage connector elements, without damage.
The present invention provides an electrical cabinet that accepts a number of individual circuit boards and further provides a mechanism for remotely interconnecting movable connector elements on each circuit board with stationary connector elements mounted within the electrical cabinet. According to one aspect of the invention, the circuit boards are grouped into a number of circuit board assemblies. Each circuit board assembly includes a frame configured to cooperate with a slot in the cabinet to align the movable connector elements on the circuit boards with the stationary connector elements in the cabinet. According to another aspect of the invention, the circuit boards each include a first mechanism acting from a remote location to gently urge the counterpart connector elements together, and a second mechanism also acting from a remote location to gently disengage the mated connector elements.
According to various aspects of the invention, the present invention provides an electrical cabinet and circuit board assembly having an electrical cabinet formed with an array of slots each having access provided adjacent to a first surface of the cabinet and a connector end adjacent to a second opposing surface of the cabinet, and one or more stationary connector elements adjacent to the connector end of the slots. Each of the stationary connector elements defines a connector engagement axis. The invention includes one or more circuit boards adapted for entry into different slots. The circuit boards each include a second connector element movable along the connector engagement axis for interconnecting with the first stationary connector element, an internally-threaded member that is positionally fixed on the circuit board relative to the connector engagement axis, and a rotary drive insertion device having a substantially flexible, externally-threaded rod executing at least one directional change between a first drive input end and a second drive output end, the drive output end engaged with both the internally-threaded member and the second connector element for moving the second connector element along the engagement axis.
According to one aspect of the invention, the flexible rod describes a predetermined curving trajectory between the first drive input end and the second drive output end that includes the directional change.
According to another aspect of the invention, a stanchion is included on the circuit board for restraining the first drive input end of the flexible rod for motion along the predetermined trajectory.
According to another aspect of the invention, a tubular guide is included on the circuit board and surrounds at least a portion of the flexible rod.
According to various other aspects of the invention, the present invention provides a circuit board assembly installation device wherein each circuit board in the assembly includes a connector element that is movable along an engagement axis with a mating fixed connector element fixed on an interface board within the cabinet. The movable connector element is formed with an insertion drive surface oriented relatively to the engagement axis. An insertion cam positioned proximately to the movable connector element includes an actuation surface facing and mating with the insertion drive surface of the moveable connector. The insertion cam is controllable from a remote location and movable perpendicular to the engagement axis of the mating connector elements. An insertion drive mechanism pushes the insertion cam along an installation axis that is substantially perpendicular to the engagement axis. A drive force applied to the insertion drive mechanism moves the actuation surface of the insertion cam along the installation axis and into contact with the insertion drive surface of the moveable connector element. Pressure of the actuation surface against the movable connector urges the movable connector element along the engagement axis toward the fixed connector element. The gentle easing of the engagement of the moveable and fixed connector elements allows sufficient opportunity for guidance mechanisms on the connector housings to orient the pins for insertion into the corresponding female receptacles.
According to one aspect of the invention, initial alignment within an electrical cabinet is provide by an array of slots within the electrical cabinet. Each slot has access provided adjacent to one surface of the cabinet and a connector end of the slot adjacent to an opposite surface of the cabinet. The stationary connector elements are provided adjacent to the connector end of the slots, for example, as components mounted on an interface board, such as a mother board, back plane, or another circuit board buried deep within the cabinet. According to various aspects of the invention, initial alignment is further provided to different circuit board assemblies, each including multiple circuit boards secured relative to a frame, by providing guides within the elongated slots that slidingly engage the frame of the circuit board assembly. Preferably, the frame is provided with either or both of a precision width dimension and a precision height dimension, while each slot is provided with a corresponding precision dimension sufficiently larger to permit a sliding fit of the frame therein.
According to various other aspects of the invention, the insertion cam is formed in a wedge-shape with an inclined surface. An inclined actuation surface of the insertion cam engages a matchingly inclined insertion drive surface on the moveable connector element. Preferably, the insertion cam is slidingly engaged with a guide channel that supports the insertion cam and directs it along the installation axis.
According to another aspect of the invention, an extraction cam is provided to disengage the moveable connector element from the stationary connector element. Accordingly, an extraction drive surface is provided on the movable connector element facing toward but spaced away from the insertion drive surface. An extraction cam configured similarly to but oppositely from the insertion cam is driven by an extraction drive on an extraction axis parallel to but spaced away from the insertion axis. An inclined surface on the extraction cam engages the extraction drive surface and gently eases the movable connector element along the engagement axis away from the fixed connector element. The extraction cam is slidingly engaged with an extraction cam guide that supports the extraction cam and directs it along the extraction axis.
According to still another aspect of the invention, the insertion and extraction drivers are alternatively either rigid or flexible threaded drive elements. According to various aspects of the present invention, the flexible drive elements are compressively wound helical coil springs threadedly engaged with internally threaded nuts matched thereto in diameter and pitch. The flexible drive elements are able to undergo directional changes that allow the drive torque to be input both spatially and dimensionally remotely from the respective insertion and extraction cams.
According to yet other aspects of the present invention, methods are provided that utilize the insertion and extraction cams in combination with the insertion and extraction drivers to alternately engage and disengage the fixed and mobile connector elements.